Circulation of water in water-tube boilers



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2 Sheets-Sheet A2V Fi1ed De'c. 15. 1919 o UDO.

mfr-7525565 'lil Patented May l, 11923 .v HAROLD la il le,

Git?, @F SCOTSTUN, SCOTLAND.

erneute-Irion waren in weren-rune norrgnns.r

Application filed December 15, 1919. Serial No. 344,804.

To alt en fiom it may concern.'

Be it lrnown that lHARoLD EDGAR Yan- Row, a subject ot the King of GreatBritain? residing in Scotstoun, Scotland, have in.- v'ented certain newand useful improvements Relating to the Circulation `ot lila-ter inlWater-'llube Boilers, ot which the 'tollowing is a specilication. f

The invention relates to means for increasing the circulation of thewater in water tube boilers. For this purpose it has been previouslyproposed to increase the circulation through the whole set of tubes by atan or propeller placed ina main circulating tube connected with theheaders of the boiler or in a pipe leading to the water drum. i

According to the invention. which relates to the type o' boiler such asthe Yarrow, in

which nests of tubes connect the water drums with the steam and waterdrum, one y or more propellers are arranged in the water drum so as topromote the upward circulation of the water in the more highly heatedtubes of the nest and the downward circulation in the less heated tubes.

In the accompanying drawings Fig. 'l is an elevation and 2 a sectionalplan of a boiler partly in section showing an arrangement according tothe invention. Fig. 3 is a plan of a water drum showing a furthermodification.

tion on the line 5-5 of Fig. 4; ot another modification. The samereference characters are used for similar partsI in all the drawings.

In the arrangement shown in Figs. 1 and 2, A is the steam and' waterdrum, B one of the water drums, D 'is a propeller placed in the drum B,E is a motor driving the propeller' D.y and F a gland at theV end of thedrum through which the propeller shaft K passes. H a rebriclr screenplaced at one end of the boiler between the steam drum A and a waterdrum B for the purpose of preventing some or all of the tubes to theright of the propeller from being eX- posed to the heat ot the tire. Thewall H is shown as extending half way trom t-he end of the drum to thepropeller D, but it may extend over the whole of this space. Thepropeller draws the water down tubes G disposed on its right anddelivers it to the steam drum A by tubes disposed its left'.

Fig. l is a sectionall elevation of a water drum and Fig. 5 a sec-y lnthe modifica-tion shown in Fig. 3, two propellers D', D2 are providedgydf, J 2 are partitions whchscreen ott sections l, l2 disposed' at eachend ot the water drum B from the central portion. rlhecirculation f isdown the tubes at the ends oit the boiler and up the tubes in thecentral portion. Thepropellers are placed in the partot the drumfurthest removedV troni the furnace side M. Holes in the partitions J',J2 corresponding to the size and position of the propellers,"allowthe'water to circulate from the section l', l2 to the central portion ofthe drinn B. As the tubes on the jfur-A nace side M vconveying theupward currents extend to the ends ofthe boiler, the sides N, N2 ofthepartitions are inclined so that these tubes are supplied vwith waterdelivered by the propellers, so that the circulation caused by thepropellers assists the convection currents set up in all the tubesconveying the upward `currents.

'y In the modification shown in Figs. 4L and 5, a central partition Odivides thepwater i drinn. B longitudinally;l there may be the 'same oradifferent number of tubes @non either side oi' the partition. One ormo-re propellers D two are shown in the example illustrated) rotate inapertures in the walls of the partitions and deliver water from theright hand and coolerside ot the partition f to the furnace side `M and,consequently, induce a downward flow in the tubes G to the right of thepartition andan upwardy llowin the tubes to the lett. f y y i Havingthus described the nature ofthel 'said invention and thebest means l.know of carrying the same into practical eiect, I

claim l y 1. In a. water tube boiler, a water drum 1 and a steam andwater drum placed at a lhigher level than said water drum, nests oftubes connecting said water drinn with said steam and water drum.y saidnests ot' tubes being arranged along the Ilongitudinal axis `oit saidwater drum, some of said tubesl beina nearer the sourcek ot' heat than'the others, a propeller placed in said water drum, a circulationproduced by said propeller :flowingy up the .more highly heated tubesand down the less highly heated tubes.

2.1n a water tube boiler7 a water drum and a steam and water drum placedat a y higher level than said water drum,` nests of tubes connectingsaid Water drum with said steam and Water drum, said nests' of tubesbeing arranged along the longitudinal axis of said Water drum, apartition in said Water drum Separating the more highly heated tubes'troni the less highly heated,

said partition having an Aaperture and a propeller in said Waterdrurnadapted to produce a circulation through said aperture from one side tothe other of said partition.

3. En a Water tube boiler, a Water drum and a 'steam drum, a cent-raivertical longitudinal partition in said Water drum, tubes connectingsaid Water drurn with said steam and Water drum, those on one side ofthe partition conveying an upward current of water and steam and thoseon the other side or' the partition conveying adownward eur rent or'Water, said partition having an aperture, and a propeller situated inSaid aperture and adapted to assist the downward circulation in thetubes on one side of the aperture and the upward circulation in thetubes on the other side of the aperture.

In testimony whereof I have signed my naine to this specification.

HAROLD E. YARROVV.`

